Fix bug #10170 with extra scrolling after C-s.

 src/xdisp.c (try_scrolling): Don't set scroll_down_p if dy is zero.

2 files changed, 8 insertions, 2 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 44f80ae4098..026aa6f0d04 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2011-12-09  Eli Zaretskii  <eliz@gnu.org>
+
+        * xdisp.c (try_scrolling): Don't set scroll_down_p if dy is zero.
+        (Bug#10170)
+
 2011-12-09  YAMAMOTO Mitsuharu  <mituharu@math.s.chiba-u.ac.jp>
 
         * unexelf.c (unexec) [NS_IMPL_GNUSTEP]: Take account of the case
diff --git a/src/xdisp.c b/src/xdisp.c
index 3ac5651975b..87bbded9208 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -14360,7 +14360,7 @@ try_scrolling (Lisp_Object window, int just_this_one_p,
     {
       int scroll_margin_y;
 
-      /* Compute the pixel ypos of the scroll margin, then move it to
+      /* Compute the pixel ypos of the scroll margin, then move IT to
          either that ypos or PT, whichever comes first.  */
       start_display (&it, w, startp);
       scroll_margin_y = it.last_visible_y - this_scroll_margin
@@ -14390,7 +14390,8 @@ try_scrolling (Lisp_Object window, int just_this_one_p,
           if (dy > scroll_max)
             return SCROLLING_FAILED;
 
-          scroll_down_p = 1;
+          if (dy > 0)
+            scroll_down_p = 1;
         }
     }